Use test config rather than system config in MenuUiNodeTypeTest

Problem/Motivation

#3221493: Add test coverage for menu order in node type form added a MenuUiNodeTypeTest to ensure that the calling of asort() in menu_ui_form_node_type_form_alter() is tested. Without the asort(), the form would sort the menus by machine name (per how config entities are ordered in a loadMultiple()) rather than by label. Therefore, the test is only effective when testing a dataset that is ordered differently by label than by machine name. The menus included in system.module config only accidentally satisfy that (it's an artifact of the 'account' menu being labeled 'User account menu'). If in the future, system.module config is changed to no longer have a menu with a different label than machine name, then this test will cease to be effective.

Proposed resolution

Change the test to create test menus with the desired properties (different order of labels than machine name) rather than relying on system.module config to have that property.